[media] v4l2-ctrls.c: add support for V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK
Normally no control events will go to the filehandle that called the
VIDIOC_S_CTRL/VIDIOC_S_EXT_CTRLS ioctls. This is to prevent a feedback
loop.
This can now be overridden by setting the new V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK
flag.
Based on suggestions from Mauro Carvalho Chehab <mchehab@redhat.com> and
Laurent Pinchart <laurent.pinchart@ideasonboard.com>.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index baafe2f..2c4e837 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -1832,7 +1832,8 @@
__u32 reserved[8];
};
-#define V4L2_EVENT_SUB_FL_SEND_INITIAL (1 << 0)
+#define V4L2_EVENT_SUB_FL_SEND_INITIAL (1 << 0)
+#define V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK (1 << 1)
struct v4l2_event_subscription {
__u32 type;